Exploring Public Helm Charts
Learn how to search for a public Helm chart on Artifact Hub.
We'll cover the following
One of the goals of this course is to learn how to use the Helm charts that already exist. In this lesson, we’ll learn how to search and examine already existing charts to be able to adjust them to our needs.
Artifact Hub#
Let’s start with officially available Helm charts. As mentioned in a previous lesson, there is a single place where we can start looking for any Helm chart. The place is called Artifact Hub.
We can start from the main page and type the name of the needed chart or, if we are not yet sure which particular chart we would like, we can browse all the packages.
On the left panel, we can find filters that can be applied to narrow the list of results. They’re grouped into several categories—application, publisher, and so on. Here is a screenshot of the results for the database Helm charts:
Once we pick a Helm chart we can view its details page. For example, here is a page for a PostgreSQL Helm chart.
The content of this page will depend on the creators of the chart. Some of them, like this one, are very descriptive and easy to understand, but some are not as much.
On the right, there are four buttons that in most cases are available to help us learn more about the chart. If we click on any of them a popup will appear with information, which may include the following:
“INSTALL”: This will contain instructions on how to install a particular Helm chart, which usually include two commands—to add a Helm repository and install a chart.
“TEMPLATES”: We’ll be talking about Helm templates in the next part of the course, but for now, we can treat templates as a blueprint for a Kubernetes object. From this information, we can find out which Kubernetes objects might be created when we install a Helm chart.
“DEFAULT VALUES”: This is a very important part and it shows a
values.yamlfile with all the default values that the Helm chart is offering to be overridden.“VALUES SCHEMA”: This is similar to the “DEFAULT VALUES” button. It provides information about the schema of a
values.yamlfile but without showing the default values.
As mentioned before, not every Helm chart will have this information specified in the Artifact Hub. But there is a work-around which, for some, is even better. We can check the source code of a specific chart in which values.yaml or each template will be included. Usually, a link to the source code would be found on the right panel under the mentioned buttons:
If there are no links to the source code, we probably would need to try to search for it either on GitHub or GitLab, the two most popular Git repository hosting services.
Here is a link to a PostgreSQL Helm chart source code on GitHub: https://github.com/bitnami/charts/tree/master/bitnami/postgresql.
The helm search hub command#
Another way of finding a Helm chart in Artifact Hub is to use a CLI helm search hub command which works very similarly to a single search field from a website. Here is the example output for finding a PostgreSQL chart:
As we can see, there are lots of results but without any information. The only way to find more about each Helm chart would be to enter the link from the first column, which takes us to Artifact Hub’s details page of a chart. This way seems less convenient than the previous one, but for some, it may be a preferable way of searching for a Helm chart.
Uninstall Helm Release
Quiz: Installing Public Helm Chart